Sinn Fein are planning a string of protests outside police stations in the North today.
It comes in the wake of yesterday's raids on the party's Stormont offices and homes in Belfast, as part of an inquiry into IRA intelligence gathering.
A former government messenger who once worked inside Castle Buildings, where the Northern Secretary John Reid and his Ministers have their offices, was among three men questioned by anti-terrorist police. A woman was also held following the raids.
Unionists are calling for punitive action against Sinn Fein, who in turn say they've been set up.
All sides are admitting the move, involving two-hundred officers, has left the peace process in its deepest crisis yet.